British athlete Mo Farah has struck gold in the 5,000 metres at the World Championships in Daegu, seven days after being pipped to victory in the 10,000 metres.

As a slow race turned into a last-lap sprint, Farah held off American Bernard Lagat and Ethiopia's Imane Merga to claim victory in 13 minutes 23.36 seconds.

The 28-year-old, who claimed double gold at the European Championships last year, came into the race as the favourite after leading the world rankings in 2011.

But it took all his new-found finishing speed to hold off almost the entire field, with only two of the 16 runners out of contention by the bell.

Farah had been happy to stay at the back of the pack in the early stages, even grabbing some water from a drinks station down the back straight on the third lap.

With 100 metres to go, Lagat - world champion over 1,500 metres and 5,000 metres in 2007 - began to threaten but Farah bravely held on to become the first British man to win a world title over 5,000 metres.

It looked like Britain would claim another gold when, just seconds after Farah's victory, Phillips Idowu jumped a season's best 17.70m in the triple jump to restore a healthy lead.

However, American Christian Taylor then produced a stunning leap of 17.96m to take the lead and relegate Idowu to the silver medal position. Idowu responded with 17.77m, but he was unable to produce anything better in the last two rounds and had to settle for silver, his 17.77m the best jump in world championship history not to win gold.

That left the stage clear for the 4x100m relays to end the competition and the final word was typically left to Usain Bolt, who anchored the Jamaican men's quartet to a comprehensive victory in a new world record of 37.04s, beating their own mark from the Beijing Olympics by 0.06s.

France took silver and St Kitts and Nevis a surprise bronze after the American and British teams failed to finish. Running the third leg, Darvis Patton appeared to collide with Britain's anchor man Harry Aikines-Aryeetey, the American crashing to the track and Aikines-Aryeetey failing to receive the baton from Marlon Devonish.